Study population. The study population will be in- or outpatients with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder stabilized on either olanzapine or clozapine (HWGL antipsychotics) (N=20), aripiprazole, ziprasidone, or a first-generation antipsychotic (LWGL antipsychotics) (n=20), and normal controls (people with no Axis I psychiatric disorder taking no antipsychotic medication) (n=20), for a total of 60 participants. All participants will be between the ages of 18 to 45 years and considered overweight (BMI greater than or equal to 25 and less than or equal to 29.9 kg/m(SqrRoot)). The pediatric population has been excluded to rule out certain hormonal effects (e.g. puberty) on eating behavior. A BMI range encompassing participants that are overweight was selected to maximize recruitment and to minimize confounding effects of BMI on eating behavior. Exclusion criteria will include weight-related conditions and current dietary restrictions.